A Handbook Of Some South Indian Grasses Part 14

[Ill.u.s.tration: Fig. 111.--Setaria verticillata.]

=Setaria verticillata, _Beauv._=

This is an annual gra.s.s, with erect, ascending, stout or slender, leafy stems, more or less branched and varying in length from 1 to 5 feet.

The _leaf-sheaths_ are smooth, glabrous. The _ligule_ is a fringe of hairs. _Nodes_ are glabrous.

The _leaf-blades_ are thin, flat, glabrous, spa.r.s.ely hairy and scaberulous, linear or linear-lanceolate, tapering to a fine point, base usually narrowed, 4 to 10 inches long and 1/4 to 3/4 inch broad.

The _inflorescence_ is a spike-like or subpyramidal panicle, cylindric or oblong, coa.r.s.ely bristly, 2 to 7 inches long, bristles one or few, studded with conspicuously reversed barbs or teeth, 1/6 to 1/3 inch long.

The _spikelets_ are ellipsoidal, obtuse, glabrous, 1/12 inch long.

There are four _glumes_. The _first glume_ is very small, broadly ovate, acute, hyaline, faintly 3-nerved. The _second glume_ is as long as the spikelet or a little shorter, ovate, subacute, thinly membranous and 5-nerved. The _third glume_ is equal to the second or a little longer, membranous and 5-nerved, paleate or empty, palea when present, is small and hyaline. The _fourth glume_ is elliptic-oblong, plano-convex, subobtuse, smooth or s.h.i.+ning, though faintly striate, coriaceous with incurved margins; _palea_ is coriaceous, as long as the glume, elliptic, faintly striate. _Stamens_ are three. _Lodicules_ are small.

[Ill.u.s.tration: Fig. 112.--Setaria verticillata.

1 and 2. Spikelets with bristles; 3, 4 and 5. the first, second and the third glume, respectively; 6. palea of the third glume; 7 and 8. the fourth glume and its palea; 9. ovary, stamens and lodicules; 10. a bit of the bristle showing the reversed barbs.]

This gra.s.s grows in shady places in very rich soils generally and is abundant in shady nooks and corners where there are rubbish heaps.

_Distribution._--Throughout India and Ceylon.

9. Pennisetum, _Pers._

These are annual or perennial gra.s.ses. Leaves are usually narrow. The inflorescence is a spike-like raceme consisting of involucellate cl.u.s.ters of shortly pedicellate spikelets, involucels consist of unequal, simple or branched bristles. Spikelets are obovoid or lanceolate, 1- to 2-flowered, persistent on their stalks, one to three in an involucel. There are usually four glumes in a spikelet. The first glume is minute or absent. The second glume is shorter than the third, membranous, 3- to 5-nerved, rarely wanting. The third glume is as long as the fourth, lanceolate, paleate or not, male or empty. The fourth glume is coriaceous, lanceolate, bis.e.xual or female. There are three stamens with linear anthers. Styles long. Lodicules are small if present. Grain is oblong, free within the hardened fourth glume and its palea.

KEY TO THE SPECIES

Bristles of the involucel slender and not 1. P. Alopecuros.

dilated at the base, and free; leaves very long.

Bristles of the involucel dilated below 2. P. cenchroides.

and connate at base.

[Ill.u.s.tration: Fig. 113.--Pennisetum Alopecuros]

=Pennisetum Alopecuros, _Steud._=

This is a perennial gra.s.s, densely tufted and growing to a height of 2 to 3-1/2 feet. Stems are stout, erect and much branched above.

The _leaf-sheaths_ are distichous, compressed, glabrous or rarely hairy.

The _leaf-blades_ are convolute, narrow, linear, coriaceous, strongly keeled, glabrous but with tufts of soft hairs at the base, 12 to 18 inches long, 1/10 to 1/6 inch broad. The _ligule_ is a ring of hairs.

The _inflorescence_ is a spike-like raceme, varying in length from 5 to 7 inches. The involucels are shortly stalked, with a few unequal bristles which are free down to the base and two to three times as long as the spikelet.

_Spikelets_ are lanceolate, acute, solitary, 3/8 inch long.

[Ill.u.s.tration: Fig. 114.--Pennisetum Alopecuros.

A and B. Spikelets front and back view; 1, 2, 3 and 4. the first, second, third and the fourth glume, respectively; 5. palea of the fourth glume; 6. the ovary, stamens and lodicules.]

The _first glume_ is very small, almost orbicular, hyaline and nerveless. The _second glume_ is about 1/3 the length of the third glume, lanceolate, ac.u.minate, 3-nerved. The _third glume_ is about 1/3 inch long, lanceolate, ac.u.minate, 7- to 11-nerved, epaleate and with infolded margins. The _fourth glume_ is a little longer than the third, lanceolate, ac.u.minate, with infolded margins 5- or 6-nerved, paleate and enclosing a complete flower. The _palea_ is lanceolate, ac.u.minate, as long as the glume. There are three _stamens_ with long, narrow, yellow anthers. _Stigmas_ are feathery. _Lodicules_ are either absent or very minute.

This is a very coa.r.s.e gra.s.s usually growing in stiff soils especially near wet places.

_Distribution._--Occurs all over Southern India both on the plains and on low hills.

[Ill.u.s.tration: Fig. 115.--Pennisetum cenchroides.]

=Pennisetum cenchroides, _Rich._=

This gra.s.s is a perennial. It consists of aerial branches and underground rhizomiferous stems, bearing thick fibrous roots and numerous buds covered by scarious sheaths. The aerial branches are tufted, erect or dec.u.mbent and geniculately ascending when in flower, much branched from the base, 6 to 24 inches long (under favourable conditions may reach even 3 to 4 feet in length).

The _leaf-sheath_ is slightly compressed, keeled, with scattered long hairs outside, shorter than the internodes. The _ligule_ is a short thin membrane fringed with hairs.

The _leaf-blade_ is linear, tapering to a very fine point 1-1/2 to 6 inches (sometimes 18 to 20 inches) by 1/8 to 1/4 inch scaberulous with fine long tubercle-based deciduous hairs scattered above, and the lower surface glabrous or with a few distantly scattered fine long hairs, broad at the base and constricted at the point of junction with the sheath.

The _inflorescence_ is a raceme of spikes, varying from 1-1/2 to 3-1/2 inches, with the spikes mostly densely arranged, though occasionally distant and not close-set, on a long; slender, p.u.b.erulous or scaberulous peduncle; _rachis_ is flexuous, flattened, grooved and scaberulous. The _spikes_ have involucels, consisting of two series of bristles, the outer bristles are horizontal or reflexed, numerous, fine, filiform, scabrid and purple above, shorter or longer than the spikelets; the inner bristles are two to three times longer than the spikelets, flattened and thickened at the base with a strong green nerve, ciliated with long tubercle-based hairs; one of the bristles is longer than the others and the bases of the bristles are connate at the very base into a ring; the upper portion of the bristles are filiform, scabrid and purple, the lower flattened portion being pale.

[Ill.u.s.tration: Fig. 116.--Pennisetum cenchroides.

1. A portion of a spike; 2 and 3. spikelets with their involucels; 4. a bristle; 5, 6, 7 and 8. the first, second, third and the fourth glume, respectively; 7a and 8a. palea of the third and the fourth glume, respectively; 9. ovary and stamens.]

_Spikelets_ are about 1/5 inch long oblong-lanceolate, one to three in a spike and sessile.

There are four _glumes_ in a spikelet. The _first glume_ is small, hyaline, ovate-lanceolate, acute, nerveless or sometimes 1-nerved. The _second glume_ is a little longer than the first, ovate, acute, about half of the third glume, hyaline, 1 to 3-nerved. The _third glume_ is ovate-lanceolate, ac.u.minate, generally 5- to 7-nerved, paleate, usually male; _palea_ is lanceolate, equal to or slightly shorter than the glume. The _fourth glume_ is as long as the third with a broad hyaline margin, 5-nerved paleate; palea as long as the glume. _Anthers_ are three, yellow, _stigmas_ white, feathery and the styles shortly united at the base. _Lodicules_ are not present.

This is the famous Kolakattai gra.s.s (Tamil) of the Coimbatore District and it grows in all kinds of soil and is capable of growing even when the soil is dry. It is readily eaten by cattle, sheep, goat and when once established is not easily killed out even by prolonged droughts. It is in flower in June, November and December.

_Distribution._--Fairly common in South India and Western India. Said to occur in Tropical Africa also.

There is a variety of this gra.s.s named _echinoides_. This differs from the type in the following respects--the inner bristles are united very much above the base and much thickened and stiffer than in the type.

(See fig. 116-3)

10. Cenchrus, _L._

The inflorescences are spike-like racemes, consisting of involucellate cl.u.s.ters of shortly pedicelled spikelets jointed on a simple rachis. The involucel consists of hardened spike-like bristles connate at the base into a short coriaceous cup, which is surrounded by erect or squarrose bristles. Spikelets one to three in each involucel, persistent, 1- to 2-flowered, with three or four glumes. The first glume is very small or absent. The second and the third glumes are subequal 5- to 7-nerved. The third glume is longer than the second with male flower or not, paleate.

The fourth glume is coriaceous, with a bis.e.xual or female flower.

Lodicules are two. Stamens are three. Styles are long, free or connate below. Grain is broad, oblong and compressed.